Clamp with improved internal cam action

ABSTRACT

A clamping apparatus, for use with an actuator, has a housing with a guide track mounted on or formed in the housing. A roller or cam operably engages with the guide track such that the cam can be moved and positioned along the guide track by way of the actuator. At least one pivoting arm is pivotally mounted on the housing adjacent to and spaced from the guide track. Each pivoting arm has an elongate slot adjacent to the shoulder. The elongate slot has two arcuate surfaces positioned parallel to each other and has two end surfaces joining the arcuate surfaces to define a closed loop surface. The cam is positioned within the elongate slot of each pivoting arm to pivot each pivoting arm between a clamped position and a released position as the cam is moved along the guide track and driven against the arcuate surfaces of each pivoting arm. The clamping apparatus can include stop members for limiting the movement of the cam and/or the range of motion for each pivoting arm, a swivel mount and/or a mounting bracket enabling the clamping apparatus to be positioned in any desired angular orientation, a lost-motion link incorporated in the internal cam action of the clamping apparatus, and/or side plates for preventing the infiltration of foreign matter in the internal cam action.

FIELD OF THE INVENTION

The present invention relates to a clamping apparatus used inconjunction with a conventional actuator, the clamping apparatus havingan improved cam-action for pivoting and positioning one or more clamparms of the clamping apparatus.

BACKGROUND OF THE INVENTION

Prior known power clamps or grippers typically include a pneumatic orhydraulic differential pressure motor with a cylinder housing fixedlymounted to a support structure. At the forward or rod end of thecylinder housing, a clamp arm or gripper jaw mounting structure isconnected to the cylinder housing to support movement of at least oneclamp arm or gripper jaw connected to the piston rod of the motor. Thejaw or clamp arm is pivoted to an open position in response toreciprocal movement of the piston rod in one direction, and is driven toa closed work piece gripping position in response to reciprocal movementof the piston rod in the opposite direction. Typical configurations ofknown power clamps can be seen in U.S. Pat. Nos. 5,152,568 and3,599,957. U.S. Pat. No. 5,152,568 discloses a gripper jaw driventhrough a linkage assembly, while U.S. Pat. No. 3,599,957 discloses aclamp arm driven through cam rollers connected to a rod and moveable inangular slots in the arm to pivot the arm.

It is also known to provide a mounting bracket rotatably mounted on thesupport with a pair of pivotally mounted plates each having a clampingarm and a cam track. The mounting bracket is known to include an annularshoulder engaging the support, where a flange draws the shoulder againstthe support to thereby selectively lock the bracket and the piston andcylinder against rotation in any of a plurality of rotational positions.

SUMMARY OF THE INVENTION

The present invention relates to a clamping apparatus having aconventional fluid operated cylinder actuator. A mounting bracket ispositionable in any one of a variety of positions with respect to alongitudinal axis of the actuator and clamp. According to the presentinvention, the clamping apparatus includes an internal cam action forthe clamp arm. The fluid cylinder actuator drives the roller or camfollower reciprocally between first and second positions in order tomove the clamp arm from the clamped position to the released position.As the roller or cam follower reciprocates, it drives the clamp arm byfollowing an arcuate cam surface or slot formed in each clamp arm. It isdesirable in the present invention to also provide the capability of aswivel mounting of the clamp arm or gripper jaw to the cylinder housingto allow the clamp to be positioned in any desired angular orientationwith respect to a longitudinal axis of the fluid cylinder actuator byrotation with respect to a circular collar extending through a mountingbracket. The clamp can be held in any desired angular orientation withrespect to the cylinder housing by tightening a locking mechanism, suchas set screws. The present invention can also provide an adjustable stopto define the angular orientation of the open clamp position. The stopmember, such as a threaded screw, can be positioned to engage an outerend of the cylinder rod as the roller or cam follower is driven towardthe released position. By threading the adjustable stop further into athreaded aperture, a maximum angle of opening for the clamp arm can belimited to a position less than a full released angular orientation,which generally corresponds to approximately 90° from the clampedposition. The internal cam action according to the present inventionprovides a cam surface or slot and cam follower in a completely enclosedhousing to prevent the infiltration of foreign matter into the cammechanism. Rubber seals can also be provided if desired extending alongthe periphery of the housing to further obstruct the infiltration offoreign matter through areas where the clamp arm extends through androtates with respect to the housing. By removing one side plate, thecorresponding clamp arm can be changed in the field withoutdisassembling the entire clamp. Different standard configurations ofclamp fingers or gripper jaws can be attached to the outer ends of theclamp arm thereby permitting easy changing of the jaw style. Sensors canalso be provided for signaling the position of the cam follower orroller to indicate the open position and/or the closed clamp position.

The present invention relates to a clamping apparatus for use with aconventional actuator, such as a fluid-operated cylinder. The clampingapparatus has a support structure defining an internal guide track onthe support structure. A slide block is engageable with the guide tracksuch that the slide block can be moved and positioned along the guidetrack by way of the actuator. At least one pivoting arm is provided.Each pivoting arm is pivotally mounted on the support structure adjacentto the guide track. Each pivoting arm has an elongate slot adjacent toone longitudinal end. The elongate slot has two arcuate surfacespositioned parallel to each other and two end surfaces which join thearcuate surfaces and thereby define the slot as a closed loop surface.The slide block supports a cam or roller positioned within the elongateslot of each pivoting arm to thereby pivot each pivoting arm between aclamped position and a released position as the slide block and rollercombination is moved along the guide track and the roller or cam issimultaneously driven against the arcuate surface and moved in theelongate slot of each pivoting arm. The present invention further canprovide selectively positionable stop members or screws for limiting themovement of the roller and/or the range of motion for each pivoting arm,a swivel mount and/or a mounting bracket which together enable theclamping apparatus to be positioned in any desired angular orientation.A lost-motion link can be incorporated into the internal cam action ofthe apparatus if desired, and side plates for preventing theinfiltration of foreign matter in the internal cam action can also beprovided.

Other objects, advantages and applications of the present invention willbecome apparent to those skilled in the art when the followingdescription of the best mode contemplated for practicing the inventionis read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawingswherein like reference numerals refer to like parts throughout theseveral views, and wherein:

FIG. 1 is a side view of a clamping apparatus in a clamped position withinternal cam-action clamp arms according to the present invention;

FIG. 2 is a side view of the clamping apparatus in a released positionaccording to the present invention;

FIG. 3 is a bottom view of the clamping apparatus in a clamped positionaccording to the present invention;

FIG. 4 is a perspective view of an internal cam action clamp accordingto the present invention with one side plate removed for illustrativepurposes;

FIG. 5 is a perspective view of a portion of the clamp housing with bothside plates and the internal cam mechanism removed for purposes ofillustration;

FIGS. 6-9 are schematic, side views of one clamp arm according to thepresent invention illustrating the interaction of the internalcam-action elements and incorporating optional motion-limiting stopmembers mounted in various alternative positions;

FIG. 10 is a schematic, side view of the clamping apparatus having asingle clamp arm in a clamped position and a lost notion link accordingto the present invention; and,

FIG. 11 is a schematic, side view of the clamping apparatus having asingle clamping arm in a released position with the lost-motion linkaccording to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A clamping apparatus 10 according to the present invention is operablyengageable with a linear reciprocal actuator 12 moveable between anextended position illustrated in FIG. 2 and a retracted positionillustrated in FIG. 1. A hollow housing 14 has a guide track 16 definedon opposing inner surfaces of the hollow housing 14. A slide block 18,best seen in FIG. 4 and FIG. 9, is operably engageable with the guidetrack 80. The slide block 18 is capable of being driven, moved, andpositioned along the guide track 80 by the actuator 12 between first andsecond end limits of movement corresponding to the retracted andextended positions respectably of the actuator 12. A cam 20 is connectedto or carried by the slide block 18 for movement along the guide track16. The cam 20 is operably connected to the actuator 12 for movementalong the guide track 80 in response to movement of the actuator betweenthe retracted and extended positions. At least one pivoting arm 22 ispivotably mounted for rotation about a pivot axis with respect to thehousing 14. The pivot axis of each pivoting arm is disposed adjacent toand spaced from the pivot axis. Each pivoting arm 22 has an elongateslot 24 disposed adjacent to and spaced from the pivot axis. The cam 20is positioned within the elongate slot 24 of each pivoting arm 22 forconverting linear reciprocal movement of the cam 20 into pivotingrotation of each pivoting arm 22. Each pivoting arm 22 is in a clampedposition when the slide block 18 or cam 20 is in the first end limit ofmovement as illustrated in FIG. 1, and each pivoting arm 22 is in areleased position when the slide block 18 or cam 20 is in the second endlimit as illustrated in FIG. 2.

The elongate slot 24 of each pivoting arm 22 is defined by two arcuatesurfaces 26 and 28 extending parallel to one another with two endsurfaces 30 and 32 joining the arcuate surfaces 26 and 28 to one anotherto define a closed loop surface. The arcuate surfaces 26 and 28 defineconvex arcuate segments with respect to the pivot axis of each pivotingarm 22. As best seen in FIGS. 4 and 6-9, each pivoting arm 22 isconnected to the housing through a pivot pin 34 defining the pivot axis.The elongate slot 24 extends convex with respect to the pivot axis ofthe pivot pin 34 having a first end surface 30 closest to the pivot pin34 and a second end surface 32 furthest from the pivot pin 34. When thepivoting arm 22 is in the clamped position, the actuator 12 is in theretracted position, and the cam 20 is disposed adjacent to the secondend surface 32 for furthest from the pivot pin 34. In response tomovement of the actuator 12 from the retracted position to the extendedposition, the cam 20 moves along the elongate slot 24 to a positionadjacent to the first end surface 30 closest to the pivot pin 34 as bestseen in FIG. 9. FIG. 9 illustrates the pivoting arm 22 in the fully openor released position.

Continuing to refer to FIGS. 6-9, at least one pivot pin 34 is supportedfrom the housing 14 or connection through each pivoting arm 22. Eachpivoting arm 22 is pivotal about the pivot axis to define a potentialrange of arm motion from the clamped position illustrated in FIG. 6 tothe fully released position illustrated in FIG. 9. An optional stopprojection 86 can be supported from the housing 14 for obstructing orabbreviating the range of arm motion in selective positions to defineselectable positions between the clamped position of FIG. 6 and thereleased position of FIG. 9. By way of illustration, a first stopprojection 36a is illustrated in FIG. 7 to restrict further arm motiontoward the released position beyond that illustrated. Further movementof the pivoting arm 22 is restricted by engagement of the pivot arm 22with the first stop projection 36a to provide a released position ofapproximately 30° open or rotated with respect to the clamped position.Correspondingly, the cam 20 is stopped at a position spaced from thefirst end surface 30 when using the optional first stop projection 36aas illustrated in FIG. 7. If a greater range of arm motion is required,the optional stop projection 36 can be positioned as illustrated at 36bin FIG. 8. The position of stop projection 36b permits further openingmovement of each pivoting arm 22 to a position of approximately 45° withrespect to the clamped position. As illustrated in FIG. 8, the cam 20 ispermitted to move closer to the first end surface 30 than that permittedin the configuration illustrated in FIG. 7, but is still spaced from thefirst end surface 30 preventing the full arm motion to the positionillustrated in FIG. 9. It should be apparent from this description thatif a second pivoting arm 22 is provided, it would appear as an invertedmirror image of that depicted in FIGS. 6 and 9 having a separate pivotpin, elongated slot and optional stop projections. The cam 20 would beextended through both elongate slots on a common axis as best seen inFIGS. 1-3.

Referring now to FIGS. 1-3, the present invention can include a swiveljoint 38 for supporting the housing 14 in any angular orientation withrespect to the actuator 12. The swivel joint 38 is connected to orcarried by the actuator 12 or mounting bracket 40. The swivel joint 38includes a plate 42 or portion of the mounting bracket 40 having acollar 44 extending outwardly from the plate 42. The housing 14 includesan aperture 46 complementary in shape to the collar 44 allowing thehousing 14 to seat on the collar 44 with the aperture 46 substantiallysurrounding the collar 44. Fastener means 48 is provided for securingthe housing 14 on the collar 44 of the swivel joint 38. The fastenermeans 48 can include one or more set screws 50 or any other suitablefastener. The swivel joint 38 permits the housing to be seated andsecured with respect to the collar 44 in any desired angular orientationwith respect to a longitudinal axis of the linear reciprocal actuator12. The mounting bracket 40 can include means 52 for supporting theclamping apparatus 10 with respect to a support structure. Thesupporting means 52 can be mounted on the plate 42 or form a portion ofthe mounting bracket 40. By way of example and not limitation, thesupporting means 52 can include a ball or semi-spherical collar 54engageable with, carried by or connected to the support structure (notshown). The outer periphery of the ball or semi-spherical collar 54 isadjustably engaged between two portions of a split ring 56 and 58respectively. The two portions of the split ring 56 and 58 are lockinglyengageable with respect to the spherical surface of the ball orsemi-spherical collar 54 when driven toward engagement with one anotherby a suitable fastener, such as bolt 60 engaging within threadedaperture 62.

As best seen in FIGS. 1-3, any suitable configuration of fingers 64 canbe connected to the outer end of each pivoting arm 22 to provide thedesired gripper jaw or end treatment. The selected set of complementaryfingers 64 can be connected to the outer ends of each pivoting arm 22 byany appropriate fasteners, such as by way of example and not limitation,bolts 66 threadably engaged within threaded apertures 68.

Referring now to FIG. 4, means 70 is provided for encasing the elongateslot 24 of each pivoting arm 22 and cam 20. The encasing means 70 caninclude a side plate or cover 72 for substantially enclosing thepivoting arm 22 with respect to the housing 14. In FIG. 4, the sideplate or cover 72 is connected to the far side of the housing 14 whilethe side plate or cover 72 on the near side of the housing 14 has beenremoved to show the internal structure of the pivoting arm 22, cam 20and the outer portion of slide block 18. The side plate 72 can bereconnected to the housing 14 by any suitable means, such as threadedfasteners connecting to the inner portion of the housing 14 or throughthe end plate 74 into the side plate 72. The encasing means 70 attachesto the housing 14 and serves to protect the elongate slot and cam fromcontamination or foreign matter that can be present in industrialproduction environments.

Referring now to FIG. 5, the inner portion of the hollow housing 14 isdepicted with the end plate, both side plates, both pivoting arms, camand slide block assembly being removed for clarity. The internal portionof the housing 14 includes first and second opposing surfaces 76 and 78defining a longitudinally extending slot 80 within the hollow housing14. The longitudinally extending slot 80 operably receives the innerportion of slide block 18 best seen in FIG. 9. The cam 20 extendsoutwardly from the inner portion of the slide block 18 to the outerportion of the slide block 18, which is supported by slot 80 located ineach side plate 72, after passing through the elongate slot 24 of thepivoting arm 22 as best seen in FIG. 4. The inner portion of the slideblock 18 includes an adapter 82, best seen in FIG. 9, for receiving theouter end of a rod extending from the linear reciprocal actuator 12 seenin FIGS. 1-3. The inner portion of the slide block 18 also includes astop-engaging surface 84. An adjustable stop 86 is threadably engagedthrough the aperture 88 formed in the inner portion of the housing 14best seen in FIGS. 5 and 9. The adjustable stop member 86 can bethreadably adjusted with respect to the hollow interior of the housing14 for abbreviating a permissible range of motion for the cam 20 alongthe guide track 80. The guide track 80 defines the permissible range ofmotion for the slide block 18 and cam 20. The abbreviating means 90,such as adjustable stop member 86, can partially limit the range of armmotion by adjusting the stop member 86 to further encroach on the endportion of the guide track 80 thereby preventing the slide block 18 fromreaching the fully extended position of the actuator 12.

Referring now to FIGS. 10 and 11, a clamping apparatus 10 according tothe present invention can also include a second arm portion 92 hingedlyconnected to the pivoting arm 22 with pivot pin 94. A lost-motion link96 is pivotally mounted with respect to the housing 14 for rotationalmovement about pin 98. The lost-motion link 96 also includes an elongateslot 100 for operably receiving a portion of the cam 20 carried by theslide block 18. The second arm portion 92 includes a linear slot 102. Asecond cam 104 is connected to or carried by the lost-motion link 96adjacent an end opposite from the elongate slot 100. The second cam 104operably engages within the linear slot 102 of the second arm portion 92for moving the second arm portion 92 in response to movement of the cam20 within the first elongate slot 24 of the pivoting arm 22 and thesecond elongate slot 100 of the lost-motion link 96. The lost-motionlink 96 is rotatably attached to the housing 14. The lost-motion linkhas a curved slot 100 for receiving the cam 20 to move the pivotingsecond arm portion 92 of the pivoting arm 22 between the clampedposition and the released position as the cam 20 is moved within theelongate slot 24 and the curved slot 100 in response to movement of theslide block 18 along the guide track 80. The cam 20 is positioned withinthe first and second elongate slots 24 and 100 for converting linearreciprocal movement of the cam into pivoting rotation of the pivotingarm 22 and second arm portion 92. The second arm portion 92 of thepivoting arm 22 is in the clamped position, illustrated in FIG. 10, whenthe cam 20 and slide block 18 are in the first end limit of movement orretracted position of the linear reciprocal actuator. The second armportion 92 of the pivoting arm 22 is in a released position, illustratedin FIG. 11, when the slide block 18 and cam 20 are in the second endlimit of movement corresponding to the extended position of the linearreciprocal actuator.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiments but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims, which scope is to be accorded the broadestinterpretation so as to encompass all such modifications and equivalentstructures as is permitted under the law.

1. In a clamping apparatus operably engageable with a linear reciprocalactuator moveable between an extended position and a retracted position,said clamping apparatus comprising: a hollow housing having a guidetrack defined on opposing inner surfaces; a slide block operablyengageable with said guide track capable of being driven, moved, andpositioned along said guide track by said actuator between first andsecond end limits of movement corresponding to said retracted andextended positions respectively of said actuator; a cam connected tosaid slide block for movement therewith; and at least one pivoting arm,each said pivoting arm pivotally mounted for rotation about a pivot axiswith respect to said housing adjacent to said guide track, and each saidpivoting arm having an elongate slot adjacent to and spaced from saidpivot axis, said cam positioned within said elongate slot of each saidpivoting arm for converting linear reciprocal movement of said cam intopivoting rotation of each said pivoting arm, such that each saidpivoting arm is in a clamped position when said slide block is in saidfirst end limit of movement and each said pivoting arm is in a releasedposition when said slide block is in said second end limit of movement.2. The clamping apparatus of claim 1, wherein said elongate slot of eachsaid pivoting arm is defined by two arcuate surfaces extending parallelto one another with two end surfaces joining said arcuate surfaces toone another to define a closed loop, said arcuate surfaces defined byconvex arcuate segments with respect to said pivot axis.
 3. The clampingapparatus of claim 1, further comprising: at least one pivot pinsupported from said housing for connection through each said pivotingarm, each said pivoting arm pivotal about said pivot axis defining arange of arm motion; and a stop projection supportable by said housingfor obstructing said range of arm motion in selective positions todefined selectable positions between said clamped position and saidreleased position.
 4. The In a clamping apparatus of claim 1 furtheroperably engageable with a linear reciprocal actuator moveable betweenan extended position and a retracted position, said clamping apparatuscomprising: a hollow housing having a guide track defined on opposinginner surfaces; a slide block operably engageable with said guide trackcapable of being driven, moved, and positioned along said guide track bysaid actuator between first and second end limits of movementcorresponding to said retracted and extended positions respectively ofsaid actuator; a cam connected to said slide block for movementtherewith; and at least one pivoting arm, each said pivoting armpivotally mounted for rotation about a pivot axis with respect to saidhousing adjacent to said guide track, and each said pivoting arm havingan elongate slot adjacent to and spaced from said pivot axis, said campositioned within said elongate slot of each said pivoting arm forconverting linear reciprocal movement of said cam into pivoting rotationof each said pivoting arm, such that each said pivoting arm is in aclamped position when said slide block is in said first end limit ofmovement and each said pivoting arm is in a released position when saidslide block is in said second end limit of movement; and a swivel jointfor supporting said housing in any angular orientation with respect tosaid actuator, said swivel joint having a plate, a collar mounted onsaid plate, said housing having an aperture complementary in shape tosaid collar such that said housing seats on said collar with saidaperture substantially surrounding said collar, means for securing saidhousing on said collar of said swivel joint, said collar permitting saidhousing to be seated and secured with respect to said collar in anydesired angular orientation with respect to a longitudinal axis of saidactuator.
 5. The clamping apparatus of claim 4, further comprising:means for supporting said swivel joint with respect to a supportstructure, said supporting means mounted on said plate of said swiveljoint.
 6. The clamping apparatus of claim 1, further comprising: meansfor abbreviating a permissible range of motion for said cam along saidguide track, wherein said guide track defines said permissible range ofmotion for said slide block and cam, said abbreviating meansincorporated in said housing, each said pivoting arm pivoting about saidpivot axis and thereby defining a range of arm motion, said range of armmotion partially limited by said abbreviating means.
 7. The In aclamping apparatus of claim 1, further operably engageable with a linearreciprocal actuator moveable between an extended position and aretracted position, said clamping apparatus comprising: a hollow housinghaving a guide track defined on opposing inner surfaces; a slide blockoperably engageable with said guide track capable of being driven,moved, and positioned along said guide track by said actuator betweenfirst and second end limits of movement corresponding to said retractedand extended positions respectively of said actuator; a cam connected tosaid slide block for movement therewith; and at least one pivoting arm,each said pivoting arm pivotally mounted for rotation about a pivot axiswith respect to said housing adjacent to said guide track, and each saidpivoting arm having an elongate slot adjacent to and spaced from saidpivot axis, said cam positioned within said elongate slot of each saidpivoting arm for converting linear reciprocal movement of said cam intopivoting rotation of each said pivoting arm, such that each saidpivoting arm is in a clamped position when said slide block is in saidfirst end limit of movement and each said pivoting arm is in a releasedposition when said slide block is in said second end limit of movement;and means for encasing said elongate slot of each said pivoting arm andsaid cam, said encasing means attached to said housing and serving toprotect said elongate slot and said cam from contamination.
 8. The In aclamping apparatus of claim 1, further operably engageable with a linearreciprocal actuator moveable between an extended position and aretracted position, said clamping apparatus comprising: a hollow housinghaving a guide track defined on opposing inner surfaces; a slide blockoperably engageable with said guide track capable of being driven,moved, and positioned along said guide track by said actuator betweenfirst and second end limits of movement corresponding to said retractedand extended positions respectively of said actuator; a cam connected tosaid slide block for movement therewith; and at least one pivoting arm,each said pivoting arm pivotally mounted for rotation about a pivot axiswith respect to said housing adjacent to said guide track, and each saidpivoting arm having an elongate slot adjacent to and spaced from saidpivot axis, said cam positioned within said elongate slot of each saidpivoting arm for converting linear reciprocal movement of said cam intopivoting rotation of each said pivoting arm, such that each saidpivoting arm is in a clamped position when said slide block is in saidfirst end limit of movement and each said pivoting arm is in a releasedposition when said slide block is in said second end limit of movement;each said pivoting arm having an articulated portion hingedly connectedto said pivoting arm opposite said elongate slot; and a lost-motion linkpivotally attached to said housing and said articulated portion atspaced locations from one another, said lost-motion link having a curvedslot for receiving said cam to move said articulated portion of saidpivoting arm between a clamped position and a released position as saidcam is simultaneously moved within said elongate slot and said curvedslot in response to movement of said slide block along said guide track.9. The clamping apparatus of claim 1, wherein said clamped position isdefined by said cam positioned within said elongate slot such that saidcam is disposed at a maximum distance with respect to said rotationalaxis.
 10. A clamping apparatus for a linear reciprocal actuator moveablebetween a retracted position and an extended position, said clampingapparatus comprising: a hollow housing having a guide track defined onopposing inner surfaces; a slide block operably engageable with saidguide track capable of being driven, moved, and positioned along saidguide track by said actuator between first and second end limits ofmovement corresponding to said retracted and extended positionsrespectively of said actuator; a cam connected to said slide block formovement therewith; and at least one pivoting arm, each said pivotingarm pivotally mounted for rotation about a pivot axis with respect tosaid housing adjacent to said guide track, and each said pivoting armhaving an arcuate slot adjacent to and spaced from said pivot axis, saidcam positioned within said arcuate slot of each said pivoting arm tothereby pivot each said pivoting arm between a clamped position whensaid slide block is in said first end limit of movement corresponding tosaid retracted position and a released position when said slide block isin said second end limit of movement corresponding to said extendedposition as said slide block is moved along said guide track and as saidcam is simultaneously moved within said arcuate slot of each saidpivoting arm.
 11. A clamping apparatus comprising: a hollow housinghaving a guide track defined on opposed inner surfaces of said housing;an actuator mountable on said housing and moveable between an extendedposition and a retracted position; a cam moveable with respect to saidguide track and connected to said actuator such that said cam is driven,moved, and positioned along said guide track by said actuator; and atleast one pivoting arm, each said pivoting arm mounted for movementabout a pivot axis with respect to said housing, said pivot axisadjacent to and spaced from said guide track, and each said pivoting armhaving an elongate slot adjacent to and spaced from said pivot axis,said cam positioned within said elongate slot of each said pivoting armto pivot each said pivoting arm between a clamped position correspondingto said retracted position of said actuator and a released positioncorresponding to said extended position of said actuator as said cam ismoved along said guide track and simultaneously driven against saidelongate slot of each said pivoting arm.
 12. The clamping apparatus ofclaim 11, wherein said elongate slot of each said pivoting arm isdefined by two arcuate surfaces extending parallel to one another withtwo end surfaces joining said arcuate surfaces to one another to definea closed loop surface, said arcuate surfaces defined by convex arcuatesegments with respect to said pivot axis.
 13. The clamping apparatus ofclaim 11, further comprising: at least one pivot pin support from saidhousing for connection through each said pivoting arm, each saidpivoting arm pivotal about said pivot axis defining a range of armmotion; and a stop projection supportable by said housing forobstructing said range of arm motion in selective positions to defineselectable positions between said clamped position and said releasedposition.
 14. The clamping apparatus of claim 11, further comprising:means for abbreviating a permissible range of motion for said cam alongsaid guide track, wherein said guide track defines said permissiblerange of motion for said cam, said abbreviating means incorporated insaid housing, each said pivoting arm pivoting about said pivot axis andthereby defining a range of arm motion, said range of arm motionpartially limited by said abbreviating means.
 15. The A clampingapparatus of claim 11, further comprising: a hollow housing having aguide track defined on opposed inner surfaces of said housing; anactuator mountable on said housing and moveable between an extendedposition and a retracted position; a cam moveable with respect to saidguide track and connected to said actuator such that said cam is driven,moved, and positioned along said guide track by said actuator; and atleast one pivoting arm, each said pivoting arm mounted for movementabout a pivot axis with respect to said housing, said pivot axisadjacent to and spaced from said guide track, and each said pivoting armhaving an elongate slot adjacent to and spaced from said pivot axis,said cam positioned within said elongate slot of each said pivoting armto pivot each said pivoting arm between a clamped position correspondingto said retracted position of said actuator and a released positioncorresponding to said extended position of said actuator as said cam ismoved along said guide track and simultaneously driven against saidelongate slot of each said pivoting arm; and means for encasing saidelongate slot of each said pivoting arm and said cam, said encasingmeans attached to said housing and serving to protect said elongate slotand said cam from contamination.
 16. The clamping apparatus of claim 1115, further comprising: each said pivoting arm having an articulatedportion hingedly connected to said pivoting arm opposite said elongateslot; and a lost-motion link pivotally attached to said housing and saidarticulated portion at spaced locations from one another, saidlost-motion link having a curved slot for receiving said cam to movesaid articulated portion of said pivoting arm between a clamped positionand a released position as said cam is simultaneously moved within saidelongate slot and said curved slot in response to movement of said camalong said guide track.
 17. The clamping apparatus of claim 11, whereinsaid clamped position is defined by said cam positioned within saidelongate slot such that said cam is disposed at a maximum distance withrespect to said rotational axis.
 18. The A clamping apparatus of claim11 wherein said at least one pivoting arm comprises comprising: a hollowhousing having a guide track defined on opposed inner surfaces of saidhousing; an actuator mountable on said housing and movable between anextended position and a retracted position; a cam moveable with respectto said guide track and connected to said actuator such that said cam isdriven, moved, and positioned along said guide track by said actuator;and at least one pivoting arm, each said pivoting arm mounted formovement about a pivot axis with respect to said housing, said pivotaxis adjacent to and spaced from said guide track, and each saidpivoting arm having an elongate slot adjacent to and spaced from saidpivot axis, said cam positioned within said elongate slot of each saidpivoting arm to pivot each said pivoting arm between a clamped positioncorresponding to said retracted position of said actuator and a releasedposition corresponding to said extended position of said actuator assaid cam is moved along said guide track and simultaneously drivenagainst said elongate slot of each said pivoting arm; and wherein saidat least one pivoting arm comprises first and second pivoting armshaving first and second pivot axes respectively on opposite sides ofsaid guide track, each pivoting arm having said elongate slot disposedbetween said pivot axis and said actuator, such that said first andsecond pivoting arms are simultaneously moveable between a clampedposition corresponding to said retracted position of said actuator and areleased position corresponding to said extended position of saidactuator.
 19. A clamping apparatus comprising: a hollow housing having aguide track defined on opposed inner surfaces of said housing; anactuator mountable on said housing; a cam moveable with respect to saidguide track and connected to said actuator such that said cam is driven,moved, and positioned along said guide track by said actuator; at leastone pivoting arm, each said pivoting arm mounted for movement about apivot axis with respect to said housing, said pivot axis adjacent to andspaced from said guide track, and each said pivoting arm having anelongate slot adjacent to and spaced from said pivot axis, said campositioned within said elongate slot of each said pivoting arm to pivoteach said pivoting arm between a clamped position and a releasedposition as said cam is moved along said guide track and simultaneouslydriven against said elongate slot of each said pivoting arm; and aswivel joint for supporting said housing in any angular orientation withrespect to said actuator, said swivel joint having a plate, a collarmounted on said plate, said housing having an aperture complementary inshape to said collar such that said housing seats on said collar withsaid aperture substantially surrounding said collar, means for securingsaid housing on said collar of said swivel joint, said collar permittingsaid housing to be seated and secured with respect to said collar in anydesired angular orientation with respect to a longitudinal axis of saidactuator.
 20. The clamping apparatus of claim 19, further comprising:means for supporting said swivel joint with respect to a supportstructure, said supporting means mounted on said plate of said swiveljoint.
 21. A clamping apparatus comprising: a fluid linear reciprocalactuator having a piston rod moveable between an extended position and aretracted position along a path of travel; a single cam operablyassociated with the piston rod for movement; and at least one armmounted for rotation about a pivot axis and having an elongate slot, thesingle cam positionable within the elongate slot of said at least onearm for converting linear reciprocal movement of the piston rod intorotation of said at least one arm, such that said at least one arm is ina clamped position when the cam is in the retracted position and said atleast one arm is in a released position when the cam is in the extendedposition.
 22. The clamping apparatus of claim 21 wherein said at leastone arm further comprises: a first arm rotatable in a first plane; and asecond arm rotatable in a second plane, the first and second planessubstantially parallel to one another.
 23. The clamping apparatus ofclaim 21 further comprising: a member having at least one slot foroperably receiving and guiding the single cam along the path of travel.24. The clamping apparatus of claim 23 wherein the member furthercomprises: a central portion having the at least one slot formedtherein; and said at least one arm including first and second armspivotally connected to the central portion.
 25. The clamping apparatusof claim 23 wherein the member further comprises: at least one sideplate mounted adjacent said central portion.
 26. The clamping apparatusof claim 21 further comprising: a cam support connectible to theactuator; and said at least one arm including first and second arms withthe cam support interposed therebetween.
 27. The clamping apparatus ofclaim 21 wherein said elongate slot of said at least one arm is definedby two arcuate surfaces defined by convex arcuate segments with respectto said pivot axis.
 28. The clamping apparatus of claim 27 wherein saidelongate slot of each said pivoting arm is defined by two end surfacesjoining said arcuate surfaces to one another to define a closed loopsurface.
 29. The clamping apparatus of claim 21 further comprising: abody having a recess for receiving the at least one arm.
 30. Theclamping apparatus of claim 29 wherein the body further comprises: atleast one cam aperture for receiving the single cam.
 31. The clampingapparatus of claim 30 further comprising: at least one side plateconnectible to the body for at least partially enclosing the at leastone cam aperture.
 32. A clamping apparatus comprising: a fluid linearreciprocal actuator having a piston rod moveable between an extendedposition and a retracted position along a path of travel; a single camcoupled to said piston rod and having two ends, the cam extendingperpendicular with respect to the path of travel; and at least one armmounted for rotation about a pivot axis and having an arcuate slotdefined by convex arcuate segments with respect to said pivot axis, oneend positionable in the arcuate slot of said at least one arm forpivoting said at least one arm between a clamped position, wherein saidcam is in the retracted position, and a released position, wherein saidcam is in the extended position.
 33. The clamping apparatus of claim 32further comprising: means for at least partially enclosing at least oneend of the single cam.
 34. The clamping apparatus of claim 33 whereinenclosing means further comprises: a body associated with the actuatorand having at least one slot for receiving the single cam; and at leastone side plate associated with the body positionable adjacent the atleast one slot.
 35. The clamping apparatus of claim 32 furthercomprising: a member having at least one slot for operably receiving andguiding the single cam along the path of travel.
 36. The clampingapparatus of claim 35 wherein the member further comprises: a centralportion having the at least one slot formed therein; and said at leastone arm including first and second arms pivotally connected to thecentral portion.
 37. The clamping apparatus of claim 35 wherein themember further comprises: at least one side plate having the at leastone slot with the at least one arm disposed between the at least oneside plate and the path of travel.
 38. The clamping apparatus of claim32 further comprising: a cam support connectible to the actuator; andsaid at least one arm including first and second arms with the camsupport interposed therebetween.
 39. The clamping apparatus of claim 32further comprising: a body having a recess for receiving the at leastone arm.
 40. The clamping apparatus of claim 39 wherein the body furthercomprises: at least one cam aperture for operably receiving and guidingthe single cam along the path of travel.
 41. The clamping apparatus ofclaim 40 further comprising: at least one side plate connectible to thebody for at least partially enclosing the at least one cam aperture. 42.The clamping apparatus of claim 39 further comprising: the at least onepivoting arm pivotally mountable with respect to the body.